If intelligent alien civilizations exist, they may have built structures so massive they’re visible across space—so-called megastructures. These could include Dyson spheres, space habitats, or stellar engines—designed to harness energy, transport populations, or even move stars.

Astronomers have speculated that if we observe unusual light fluctuations—like irregular dimming or excess infrared radiation—it could point to alien engineering. This was the case with Tabby’s Star, which sparked theories about a Dyson swarm (though the true cause was dust).

Alien megastructures wouldn’t look like our buildings—they’d likely be functional and energy-efficient, not aesthetic. Imagine solar-collecting satellites, ringworlds encircling planets, or planet-sized computers processing data for an entire civilization.

Detecting such structures requires high-resolution telescopes and AI algorithms to analyze anomalies in stellar behavior. These observations are part of the search for technosignatures—evidence of advanced alien tech.

While we’ve found no confirmed megastructures yet, the universe is vast. If we ever detect one, it would prove not only that we’re not alone—but that intelligence can persist and thrive at unimaginable scales.

In the hunt for life, we may first find not aliens—but the cosmic footprints of their technology.